Ornamental convection lamp



sept 29, 1970 J. l.. HANCOCK 3,531,635

ORNAMENTAL CONVECTION LAMP Filed OCt. 19, 1967 United States Patent Office 3,531,635 Patented Sept. 29, 1970 U.S. Cl. 240- 8 Claims ABSTRACT OF THE DISCLOSURE A transparent container holding a liquid and a plurality of discrete metallic flakes is positioned in close proximity to an incandescent electric light bulb. When the bulb is energized, convection currents are created in the liquid so that the metallic flakes travel and give off a shimmering attractive effect.

This invention relates to devices which produce `ornamental and decorative lighting effects and more particularly to a liquid-filled lamp which produces attractive and eye catching animated effects.

Devices for producing animated visual effects are wellknown and have taken a variety of forms ranging from manually agitatable crystal spheres to heat motivated bubble lights employing a single liquid of 10W boiling point or a pair of immiscible liquids of different densities Wherein the heavier liquid is capable of expanding or changing from a liquid into a gas and :back again at given critical temperatures.

While each of the prior animated devices had its own peculiar appeal, that appeal necessarily was limited by the presence of certain inherent undesirable features. Thus, for exampjle, manual operation was obviously unsatisfactory and produced only a transient effect, whereas the simple bubbling of a liquid soon became monotonous and boring to the observer. Lamps with immiscible liquids were relatively expensive and invariably required substantial heat and a lengthy warm-up period to begin operation. In addition, it was difficult to maintain the necessary critical temperatures so that overheating sometimes caused a damping or cessation of the intended action.

It is therefore an important object of this invention to provide a novel animated lamp which is free of the undesirable limitations described hereinabove.

Another object is to afford an animated lamp of the character described which is ornamental and operates automatically and continuously utilizing the convection currents in a heating or heated liquid.

A further object is to provide an ornamental convection lamp of the character described which requires very little heat to begin and maintain operation.

Still another object is to afford an ornamental convection lamp of the character described which requires little or no warm-up period and begins operation almost instantaneously with the application of heat thereto.

Yet another object is to provide an ornamental convection lamp of the character described which employs only one liquid and does not require the maintenance of any critical temperatures for the continued operation thereof.

Still a further object is to afford an ornamental convection lamp of the character described which may be inexpensively manufactured and yet produces a most attractive and appealing kaleidoscopic effect.

With the foregoing and other objects in view which will appear as the description proceeds, the invention comprises generally a transparent container filled with a liquid which may include water, but which preferably has a viscosity greater than water. Likewise positioned in the container is a plurality of discrete fragments or flakes of a suitable metal or alloy which have shiny or reflective surfaces. The container is positioned in close proximity with and preferably above a small incandescent electric light bulb. When the light bulb is energized, the convection currents generated in the liquid cause the metal flakes ttif move and create a shimmering and constantly changing e ect.

For the purpose of facilitating an understanding of my invention, I have illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, my invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same characters of reference are employed to indicate corresponding or similar parts throughout the several figures of the drawings:

FIG. 1 is a front elevational view of an ornamental convection lamp embodying the principles of the invention and showing the same incorporated in an electric clock;

FIG. 2 is a vertical sectional view of the tubular liquid unit in a cold condition wherein the metallic flakes are at rest and no motion is produced;

FIG. 3 is a similar view but showing the liquid unit in operation with the metallic flakes in motion responsive to the heat from an incandescent electric bulb; and

FIG. 4 is an enlarged sectional view taken on the plane of line 4-4 in FIG. l and showing the heat and light reflecting enclosure for the electric bulb.

Referring to the various figures of the drawings, it will be seen that the reference numeral 10 indicates generally an ornamental convection lamp embodying the principles of the invention. The lamp 10 comprises a transparent tube 12 which may be made of glass or suitable plastics. For ease of assembly, the tube 12 is open at the top and closed by a removable cap 14 threadedly or frictionally retained thereon.

Filling or substantially filling the tube 12 is a liquid 16 which ideally is transparent and also possesses other physical characteristics to be subsequently described. Positioned within the liquid 16 is a plurality of discrete metallic particles or flakes 18. As indicated in FIG. 2. of the drawings, the flakes 18 fall to the bottom of the tube 12 when the lamp is in a cold or inoperative condition.

An yelectric incandescent bulb 20 is positioned in actual contact with, or close proximity to, the bottom of the tube 12. When the bulb 20 is energized, the radiated heat acts upon the liquid 16 to generate convection currents therein. The metallic flakes 18 are sufficiently Ilight in weight and small in size to be moved and carried by the convection currents in the liquid. The result is an appealing scintillating effect in which the metallic flakes lare in constant motion thoroughly dispersed throughout the entire volume of the liquid and also reflect in all directions the light radiated from the bulb 20.

After continued experimentation, it has been found that the most pleasing effects are obtained when the convection currents are not too swift or violent and when the metallic flakes appear to be moving randomly and rising and falling at substantially the same speed. To this end, it is desirable to achieve a nice balance between the viscosity of the liquid and the weight and size of the metallic flakes. In the embodiment illustrated, the liquid 16 comprises a solution of propy'lene glycol and 10% distilled water, and the flakes 18 are made of aluminum foil approximately 5 to 6 microns thick and 1A; to 1A inch square.

Alternative liquids include solutions of glycerine and Water, mineral oil and a chlorinated solvent (such las carbon tetrachloride), or water -having sugar or a salt dissolved therein. Similarly, the flakes may be made of any metal which is sufficiently malleable and light reflective, such as gold, silver, bronze, tin, copper, etc.

Turning to FIG. 4 of the drawings, it will be seen that there is provided a heat and light reflective enclosure 21 for the bulb 20. The said enclsoure comprises a split ring having a pair of thicknesses of reflective foil coated asbestos 22 and 24 sandwiched around a rigidifying metal core 26 and a flat bottom sheet 28 of reflective foil coated asbestos. The described arrangement is extremely efficient as attested to by the fact that in the embodiment illustrated the tube 12 comprises a glass bottle 1% inch in diameter and 6 inches long, and the bulb 20 is rated at only 10 watts, but motion of the flakes begins approximately 30 to 45 seconds after energization of the blub and continues uninterruptedly thereafter. At the same time, virtually all of the bulbs radiated light is reflected up into the tube 12 so that the moving metallic flakes are scintillatingly bathed in light.

The kaleidoscopic effect of the lamp 10 may be further enhanced by the positioning of a curved reflector 30 behind the tube 12, which reflector may be silvered or any other desired color. yAs will be appreciated the lamp 10 may comprise a self-contained unit or may be employed in any variety of useful or decorative devices. Thus, in FIG. 1 of the drawings, the lamp 10 is shown incorporated in a clock C having a display recess R, a removable base B which supports the reflective enclosure 21 and a switch S for selectively energizing the bulb 20.

An heat source which also radiates light can function to produce the pleasing visual effects described. It will thus be appreciated that other light radiating heat sources, such as a candle or a gas flame, may be substituted for the bulb 20.

It is believed that my invention, its modes of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that while a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are nonetheless capable of wide variation within the purview of my invention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United States is:

1. An ornamental convection lamp comprising:

a transparent container;

a transparent liquid within said container;

a plurality of discrete metallic flakes in said container;

and a heat source adjacent the lower end of said container for generating convection currents in the liquid;

said liquid having a viscosity greater than water and a boiling point higher than the temperature to which the same can be raised by said heat source; and

said metallic flakes being of a surface area and weight so that they are capable of being carried by convection currents in said liquid toward the surface of the liquid and back down to the bottom of the container.

2. The lamp of claim 1 in which said container comprises an elongated glass tube open at the top thereof; and

a cap removably closing said container top.

3. The lamp of claim 1 in which said liquid is selected from a group of solutions consisting of propylene glycol and water, glycerine and water, mineral oil and a chl-orinated solvent, and water containing a dissolved sugar or salt; and

said metallic flakes are made from a metal selected from a group consisting of aluminum, gold, silver, bronze, tin and copper.

4. The lamp of claim 1 in which said liquid cornprises a solution of propylene glycol and 10% water; and

said metallic flakes comprise aluminum foil 5 to 6 microns in thickness and 1A; to 1A inch in rectangular dimension.

5. The lamp of claim 1 in which said heat source comprises an incandescent electric blub,

said moving metallic flakes reflecting in scintillating effect the light radiated from said bulb.

6. The lamp of claim 5 and comprising further a heat and light radiating enclosure for said bulb and adapted to direct the heat and light from said bulb up into said container.

7. The lamp of claim 6 in which said enclosure comprises a split ring having a pair of thicknesses of reflective foil coated asbestos sandwiched around a rigidifying metal core, and a bottom sheet of reflective foil coated asbestos.

8. The lamp of claim 5 in which an arcuate reflector is positioned behind said container for multiplying and magnifying said scintillating effect.

References Cited UNITED STATES PATENTS 5/1932 Green 240-10 X 9/1951 Silver et al. 240-10 X U.S. Cl. X.R. 10--10622 

